import React, { Component } from 'react';
import { nanoid } from 'nanoid';
import PropTypes from 'prop-types'

import './index.css'

class Header extends Component {

    // 对接受的props进行限制
    static propTypes = {
        addTodo: PropTypes.func.isRequired
    }

    keyUp = (even)=> {
        // 结构even，获取keyCode和target
        const {keyCode, target} = even
        // 判断是否是回车按键
        if (keyCode !== 13) {
            return
        }
        if (target.value.trim() === '') {
            alert('输入不能为空')
            return
        }
        // 准备好一个对象
        const todo = {id:nanoid(),name:target.value,done:false}
        this.props.addTodo(todo)
        target.value = ''
    }

    render() {
        return (
            <div className="todo-header">
                <input onKeyUp={this.keyUp} type="text" placeholder="请输入你的任务名称，按回车键确认"/>
            </div>
        );
    }
}

export default Header;